REPAIRING AND NOT THROWING AWAY

REPAIRING AND NOT THROWING AWAY

Richtige Fernseher haben Röhren!

Richtige Fernseher haben Röhren!

In Brief: On this site you will find pictures and technical information about Service Modes, Circuit Diagrams, Firmware Update procedure, Disassemble procedure, Universal remote control set-up codes, Troubleshooting and more....

If you go into the profession, you will obtain or have access to a variety of tech tips databases HERE IT IS Master Electronics Repair !.

These are an excellent investment where the saying: 'time-is-money' rules. However, to learn, you need to develop a general troubleshooting approach - a logical, methodical, method of narrowing down the problem. A tech tip database might suggest: 'Replace C536' for a particular symptom. This is good advice for a specific problem on one model. However, what you really want to understand is why C536 was the cause and how to pinpoint the culprit in general even if you don't have a service manual or schematic and your tech tip database doesn't have an entry for your sick TV or VCR.

While schematics are nice, you won't always have them or be able to justify the purchase for a one-of repair. Therefore, in many cases, some reverse engineering will be necessary. The time will be well spent since even if you don't see another instance of the same model in your entire lifetime, you will have learned something in the process that can be applied to other equipment problems.
As always, when you get stuck, checking out a tech-tips database may quickly identify your problem and solution.In that case, you can greatly simplify your troubleshooting or at least confirm a diagnosis before ordering parts.

Happy repairing!
Today, the West is headed for the abyss. For the ultimate fate of our disposable society is for that society itself to be disposed of. And this will happen sooner, rather than later.

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..............The bitterness of poor quality is remembered long after the sweetness of todays funny gadgets low price has faded from memory........ . . . . . .....
Don't forget the past, the end of the world is upon us! Pretty soon it will all turn to dust!

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Monday, 2 March 2020

REPAIR / SERVICING TV LG 47LB720V

Technical description and composition of the LG 47LB720V TV, panel type and applicable modules. The composition of the modules.
LG LED
Model: 47LB720V
Chassis / Version: LD42B
Panel: LC470DUH (PG) (F1)
LED backlight: 6920L-0504A, 6920L-0505A, 6920L-0506A, 6920L-0507A
LED driver (backlight): integrated into PSU
PWM LED driver: iW7025-00
Power Supply (PSU): EAX65424001 (2.2)
PWM Power: NCP1034DG, MAP8800 (PFC), ICE3BR4765JZ
MOSFET Power: 13N60M2
MainBoard: EAX65384004 (1.5) // EAX65384003 (1.2)
IC MainBoard: CPU: LG1311; DRAM: H5TQ4G63AFR-PBC; EEPROM: AT24C256C, EMMC: THGBMAG6A2JBAIR
Tuner: TDJM-G101D EBL1400501
Control: WiFi: 2703H-LGSBW41
Specifications 47LB720V
LG 47LB720V
General repair guidelines for TV LCD LED
Possible malfunctions
- LG 47LB720V TV does not turn on at all. There is no reaction to the remote control and control buttons from the front panel. Indicator lights do not light or flash.
With such manifestations, a malfunction is most likely to be detected in the EAX65424001 power supply module. In the absence of the necessary supply voltages in the secondary circuits of the converters, it is necessary to check the power switches (13N60M2) and rectifier diodes for a possible partial or complete breakdown.
In case of any breakdowns in the secondary circuits, the converter can operate in emergency short circuit mode, and during short circuit in the power elements of the primary circuit, the mains fuse or the current sensor at the source of the key more often breaks.
Mos-Fet keys used in switching power supplies usually fail due to a malfunction of other elements that can put it out of operation in key mode or provoke an excess of the maximum current or voltage. These can be circuits supplying the PWM controller, damping or frequency-setting circuits, or elements of OOS (negative feedback) in the stabilization circuit. PWM controllers (PWM) NCP1034DG, MAP8800 (PFC), ICE3BR4765JZ, in the absence of external damage and short circuit between the terminals, are checked by replacing with obviously good ones.
- There is no image, there is sound, it is responding to the remote control. Or immediately after turning on for a second, the image may appear and immediately disappear.
In most of these cases, a malfunction is detected in the nodes and backlight elements of the LED panel. The reason for this may be a break in the LED circuit, or a problem in stabilizing their power supply.
To check the LED strips, to open all the transitions of the LEDs, several tens of volts or more are needed, it is best to use a current source for such purposes. The breakage of several PN junctions connected in series cannot be detected with a multimeter or tester. In such cases, it is necessary to open the panel and check each LED. If your multimeter cannot open the LED transitions in forward bias, sometimes you can detect the presence of a PN junction of the protective zener diode by connecting the probes in the opposite direction. If the zener diode is broken or broken in short-circuit, then the LED is faulty and needs to be replaced.
- The TV does not turn on, does not respond to the remote control. The indicator blinks or signals standby mode.
Repair or diagnostics of the EAX65384004 motherboard should begin by checking the stabilizers and power converters needed to power the chips and matrix. If necessary, update or replace the software (software). Sometimes they require checking or replacing (if necessary) the elements of the MainBoard - CPU: LG1311; DRAM: H5TQ4G63AFR-PBC; EEPROM: AT24C256C, EMMC: THGBMAG6A2JBAIR. In cases where the BGA processor is used, its malfunction is usually detected by the local heating method.
If the TV works normally from external devices, but does not tune into television channels, the TDJM-G101D EBL1400501 tuner may be malfunctioning. In such cases, first of all, you should make sure that there are supply voltages at its corresponding conclusions. It is also necessary to make sure that the tuner and processor can exchange data via the I2C bus. Sometimes the cause of the inoperability of the tuner may be a software failure.
Attention to users! Self-repair of the LG 47LB720V TV without the appropriate qualifications and the necessary experience can lead to its complete non-repairability!
Service manual and schematic diagram LG 47LB720V Chassis LD42B


 The appearance of the MainBoard EAX65384004 is shown in the figure below:
EAX65384004
EAX65384004 can be used in TVs:
LG 32LB650V ZE (Panel LC320DUH (FG)(P2)), LG 47LB650V ZE (Panel LC470DUH (FG) (P2)), LG 42LB650V (Panel LC420DUH (FG)(P2)), LG 42LB671V ZF (Panel LC420DUH (PG) (F1)), LG 47LB671V (Panel LC470DUH (PG)(F1)), LG 42LB653V ZK (Panel LC420DUH (FG)(P1)), LG 42LB720V (Panel LC420DUH (PG)(F1)), LG 42LB658V (Panel LC420DUH (FG)(P2)), LG 47LB677V (Panel LC470DUH (FG)(F1)), LG 42LB679V (Panel LC420DUH (PG)(F1)), LG 47LB653V (Panel LC470DUH (FG)(P1)), LG 32LB653V (Panel LC320DUH( FG)(P1)), LG 42LB690V (Panel LC420DUH (PG)(F1)), LG 55LB630V (Panel LC550DUH).
The appearance of the power supply
Main features of the device LG 47LB720V:
Installed matrix (LED-panel) LC470DUH (PG) (F1).
To power the backlight LEDs, a converter is used, combined with a power supply, controlled by the iW7025-00 PWM controller.
The necessary supply voltages for all nodes of the LG 47LB720V TV are generated by the EAX65424001 power module or its analogs using NCP1034DG, MAP8800 (PFC), ICE3BR4765JZ microcircuits and 13N60M2 type power switches.
MainBoard - the main board (motherboard) is an EAX65384004 module, using CPU chips: LG1311; DRAM: H5TQ4G63AFR-PBC; EEPROM: AT24C256C, EMMC: THGBMAG6A2JBAIR and others.
Tuner TDJM-G101D EBL1400501 provides the reception of television programs and tuning to channels.
Additional technical information about the panel:
Brand: LG Display
Model: LC470DUH-PGF1
Type: a-Si TFT-LCD, Panel
Diagonal size: 47 inch
Resolution: 1920x1080, FHD
Display Mode: IPS, Normally Black, Transmissive
Active Area: 1039.68x584.82 mm
Surface: Antiglare (Haze 1%), Hard coating (2H)
Brightness: 400 cd / m²
Contrast Ratio: 1400: 1
Display Colors: 1.06B (8-bit + Dithering), CIE1931 72%
Response Time: 8/10 (Tr / Td)
Frequency: 120Hz
Lamp Type: WLED Without Driver
Signal Interface: EPI, 100 pins
Voltage: 12.0V
Posted By: FRANK at 06:11
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